Device for making threaded connections, including Luer lock connections

ABSTRACT

A device comprising an outer part and an inner part accommodated in the outer part wherein longitudinal grooves are provided within the inner part so as to receive longitudinal ribs of an injection needle. Protrusions that are disposed on the outer part and recesses which are arranged within the inner part allow the inner part to be twisted only in one direction relative to the outer part while putting up resistance to said twisting movement. A spring tenses the outer part and the inner part counter to each other in an axial direction.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of International Patent Application No. PCT/CH2003/000759, filed on Nov. 17, 2003, which claims priority to Swiss Application No. 1988/02, filed on Nov. 25, 2002, the contents of which are incorporated in their entirety by reference herein.

BACKGROUND

The present invention relates to devices and methods for attaching, coupling or making connections, including threaded connections, and, more particularly, to a device for screwing together medium-guiding threaded connections, particularly Luer-lock connections.

Such connections may comprise an outer part and an inner part that is rotatably accommodated therein, which inner part has available means to accommodate a thread-bearing connection part or an additional part rotationally secured to the former, and impeding means being available that allow a rotation of the inner part in only one direction relative to the outer part and that oppose a resistance to this rotation.

Luer-lock fastenings are frequently used in the area of medical technology, in order to connect together parts in the interior of which a medium flows, especially a fluid. For example, infusion containers and associated tubes or injection syringes and associated needles frequently use such fastenings or connections. So that such connections are tight and do not loosen, they must be tightened with a certain torque. On the other hand, most of the threaded parts, particularly those made of plastic, must not be tightened too strongly because otherwise they can break.

SUMMARY

One object of the present invention is to provide a device and method for making and/or tightening fluid-guiding threaded connections, including Luer-lock type connections, wherein the device can be produced simply and cost effectively, is simple to operate, and reliably limits, above and below, the torque in the tightening of the threaded connection.

The present invention addresses this object by providing that the resistance when rotating increases up to a maximum load and subsequently falls off sharply. The resistance may be derived from a suitably shaped surface, such as a surface shaped in the manner of saw teeth, where the sharp fall-off or decrease of the torque of the device can be discerned tactilely and/or acoustically by the operator, and it is signaled to the operator that the desired torque for screwing on the threaded connection has been achieved.

In one embodiment, the present invention comprises a device comprising an outer part and an inner part accommodated in the outer part wherein longitudinal grooves are provided within the inner part so as to receive longitudinal ribs of an injection needle. Protrusions that are disposed on the outer part and recesses which are arranged within the inner part allow the inner part to be twisted only in one direction relative to the outer part while putting up resistance to said twisting movement. A spring tenses the outer part and the inner part counter to each other in an axial direction.

In one embodiment, the present invention comprises a device including an outer part and an inner part, wherein the outer and inner parts are complementary so that the inner part can be moved in one direction relative to the outer part against resistance.

According to a preferred embodiment of the present invention, the means for accommodation consist of a bore in the inner part having longitudinal grooves arranged axially therein. These longitudinal grooves accommodate longitudinal ribs on a conventional needle carrier of the Luer-lock type or on a supplementary part and, thus, ensure a reliable transfer of the tightening torque. In one embodiment, the supplementary part is preferably a needle protective cap placed on the connection part.

According to another embodiment of the present invention, the impeding means exhibit generally axially-directed protrusions arranged in an outer part which work in conjunction with generally axially-directed recesses arranged on an inner part, and spring means that press the outer part and the inner part against each other in the axial direction. These protrusions and recesses can advantageously effect a tactile and visible periodic axial displacement of the inner part with respect to the outer part. It is understood that a kinematic reversal of this principle is also possible, where the recesses are arranged in the outer part and the protrusions are arranged on the inner part.

Another embodiment of the present invention provides for the impeding means to exhibit essentially radially-directed protrusions arranged in the outer part that work in conjunction with essentially tangentially directed blades arranged on the inner part, wherein the blades are formed so as to be resilient in an essentially radial direction. This allows a simple realization of the device with only two parts. Naturally, here also the kinematic reversal is possible, the protrusions being arranged on the inner part and the blades in the outer part.

Another aspect of the present invention relates to a loading station for the preparation of an injection device that contains a device according to the invention. The loading station can contain other functional elements that serve the preparation of an injection device, in particular an autoinjector. The device according to the present invention is preferably removably accommodated in the loading station. In one embodiment, the loading station is designed as a container for storage of the parts of an injector device. This makes it possible for the user of an injection device to carry the necessary individual parts with him and to store them in clear view.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an injection needle with a Luer-lock connection;

FIG. 2 is a partially exploded view, obliquely from above, of an embodiment of the device according to the present invention;

FIG. 3 is a partially exploded view, obliquely from below, of the embodiment according to FIG. 2;

FIG. 4 is a longitudinal section through the embodiment according to FIGS. 2 and 3;

FIG. 5 is a view, obliquely from below, of another embodiment of a device according to the present invention;

FIG. 6 is a longitudinal section through the embodiment according to FIG. 5; and

FIG. 7 is a perspective view of a loading station for an injection device, with a device for screwing on or making a threaded connection.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an example of an injection needle 1 with a needle carrier 2 made of plastic, into which is cast a cannula 3 made of metal. The needle carrier 2 exhibits two tabs 17 on its upper edge, the tabs assuming the function of an outer thread that can be screwed into a corresponding inner thread in order to connect the injection needle with a syringe. Formed outside on the needle carrier 2 are ribs 4, which are accommodated by the corresponding longitudinal grooves in a needle protective cap 18 and thus form a rotationally-fixed connection with the cap. The needle protective cap 18, for its part, exhibits external ribs 19, which likewise serve to transfer torque. The embodiments described below of a device and method according to the present invention for screwing on fluid-guiding threaded connections are intended for, among other uses, injection needles of this kind.

The embodiment of the device of the present invention represented in FIGS. 2 to 4 exhibits an outer sleeve 5 that is connected to a base 6 by means of a snap connection 7. So that the sleeve 5 cannot turn relative to the base 6, the two parts are provided with a toothing, or teeth 8. Supported in the sleeve 5 is a rotation part 9 that exhibits an axial opening in which longitudinal grooves 11 are present for accommodating the ribs 19 of the needle protective cap 18. A spring 12, such as a compression spring, is located between the sleeve 5 and the rotation part 9, the spring being supported axially on an upper edge 15 of the sleeve 5 and on a lower flange 10 of the rotation part 9 and pressing the rotation part 9 against the base 6. On this base 6 are arranged a number, in the present example four, of protrusions 13, each of which has a vertical side and an inclined side. Incorporated into the lower front side of the rotation part 9 are recesses 14, which correspond in number and form to the protrusions 13. Now, for example, if an injection needle 1 is introduced into the rotation part 9, the ribs 4 at the needle carrier 2 engage the longitudinal grooves 11 of the rotation part 9, so that the needle carrier 2 cannot turn in the rotation part 9. If the syringe is now turned in the clockwise sense, there occurs at first a relative rotation between the syringe and the needle carrier 2, whereby the thread is tightened. If a predetermined minimal torque is reached, the rotation part 9 begins to turn relative to the sleeve 5. In the process, the recesses 14 of the rotation part slide over the protrusions 13 of the base 6, whereby the rotation part is raised so far against the force of the spring 12, in the present example after a turning angle of 90°, that the recesses 14 are again flush with the protrusions 13. At this moment, the rotation part 9 is thrust downward by the spring 12 and strikes the base 6, whereby, due to the feel as well as the sound, the user is alerted to the fact that the desired torque has been achieved. The longitudinal ribs 16 present on the outer periphery of the sleeve 5 serve, on the one hand, to provide a better hold when the device is held in the hand, and on the other hand serve as a protection against rotation when the device is arranged in a loading station, as is described further below.

FIGS. 5 and 6 show a second embodiment of a device according to the present invention which comprises two parts, namely a sleeve 25 and a rotation part 29 arranged in the sleeve, both of which can be produced of a mutable material, such as plastic, by the injection molding process. The rotation part 29 exhibits, in its lower part, tangentially formed-on blades 33. These blades 33 act as spiral springs and, upon a turning of the rotation part 9, are guided past the longitudinal ribs 28 formed inside on the rotation part, the blades 33 yielding radially in an elastic manner. After passing the longitudinal ribs 28, the blades 33 again spring outward, whereby a clicking sound occurs that signals the user that the desired torque has been achieved. This device is simple to assemble in that the rotation part 29 is pushed into the sleeve 25 from above, the blades 33 in the upper, slightly conical part of the sleeve 25 deforming symmetrically inward and, after passing the step 27 of the sleeve 25, snapping outward. The rotation part is thus held at the top. At the bottom, the rotation part 29 is held in the sleeve 25 by means of an upper edge 30 formed on the rotation part 29, which edge rests against a further step 26 of the sleeve 25. In this embodiment, also provided at the outer periphery of the sleeve 25 are longitudinal ribs 36, which serve for better holding when the device is held in the hand, or serve as rotation protection when the device is arranged in a loading station, as is described below.

In the two exemplary embodiments of the present invention the inner part 9 or, as the case may be, 29, can only be turned in one direction and is blocked in the opposite direction. Thus, a device according to the present invention can also be used for loosening threaded connections.

FIG. 7 shows one embodiment of a loading station 40 for the preparation of an autoinjector. Autoinjectors can serve for self-administration of medications for a patient. Autoinjectors usually operate through spring force, whereby in an automatic manner, an injection needle is first inserted and then an agent is expelled. If an autoinjector is fitted for use with filled syringes, then the stressing of the spring, the placing of the injection needle onto the syringe, and the introduction of the syringe into the autoinjector are part of the preparation process. Elements that enable this preparation or make it easier can, for example, include a tension pin 43 which serves the stressing of the spring, and a receptacle (44) (not shown) can be provided for an assembly aid, with the help of which the autoinjector can be put together after the introduction of the syringe. Furthermore, a loading station 40 can be fitted with storage depressions 40 and 41, which serve for the storing of the autoinjector or its parts and/or the storing of the mentioned assembly aid. A loading station can further contain a device 45 such as was described above by way of the two exemplary embodiments and which serves the tightening of the threaded connection between the injection needle and the syringe. In some embodiments, the device 45 is preferably removably accommodated in and/or complemented by a cylindrical depression of the loading station, which depression exhibits longitudinal grooves for receiving the longitudinal ribs 16 or 36 of the device.

While exemplary embodiments, including preferred embodiments, of the present invention have been described herein, it is contemplated that various modifications could be made without deviating from the spirit of the present invention. Accordingly, it is intended that the scope of the present invention be dictated by the appended claims. 

1. A device comprising an outer part and an inner part, wherein the outer and inner parts are complementary and the inner part is moveable in one direction relative to the outer part against resistance.
 2. A device comprising an outer part and an inner part accommodated in the outer part wherein longitudinal grooves are provided within the inner part to receive longitudinal ribs of an injection needle, wherein protrusions are disposed on the outer part and recesses are arranged within the inner part to allow the inner part to be twisted only in one direction relative to the outer part while putting up resistance to said twisting, and wherein a spring tenses the outer part and the inner part counter to each other in an axial direction.
 3. A device for making threaded connections comprising an outer part and an inner part rotatably accommodated therein, the inner part having means for accommodating a thread-bearing connection part or an additional part that is rotationally secured to the connection part, impeding means for permitting rotation of the inner part relative to the outer part in one rotational direction only and for providing resistance to the rotation, wherein the resistance increases during the rotation up to a maximum load and subsequently falls off sharply.
 4. The device according to claim 3, wherein the means for accommodating comprises a bore in the inner part, said bore having longitudinal grooves arranged axially therein.
 5. The device according to claim 3, wherein the impeding means exhibits generally axially-directed protrusions arranged in the outer part, said protrusions working in conjunction with generally axially-directed recesses arranged in the inner part, further comprising spring means being present that press the outer part and the inner part against each other in an axial direction.
 6. The device according to claim 3, wherein the impeding means exhibits generally axially-directed recesses arranged in the outer part, the recesses working in conjunction with generally axially-directed protrusions arranged in the inner part, further comprising spring means for pressing the outer part and the inner part against each other in an axial direction.
 7. The device according to claim 3, wherein the impeding means exhibits generally axially-directed protrusions arranged in the outer part, said protrusions working in conjunction with generally tangentially-directed blades arranged on the inner part, the blades being designed to be elastic in a generally radial direction.
 8. The device according to claim 3, wherein the impeding means exhibits generally axially directed protrusions arranged on the inner part, the protrusions working in conjunction with generally tangentially directed blades arranged in the inner part, the blades being designed to be elastic in generally radial direction.
 9. The device according to claim 3, further comprising a needle protective cap placed onto the connection part.
 10. A loading station for the preparation of an injection device, said loading station comprising a device for making threaded connections comprising an outer part and an inner part rotatably accommodated therein, the inner part having means for accommodating a thread-bearing connection part or an additional part that is rotationally secured to the connection part, impeding means for permitting rotation of the inner part relative to the outer part in one rotational direction only and for providing resistance to the rotation, wherein the resistance increases during the rotation up to a maximum load and subsequently falls off sharply.
 11. The loading station according to claim 10, wherein the device is removeably accommodated in the loading station.
 12. Loading station according to claim 11, wherein the loading station is designed as a container for storage of parts of an injection device. 